Most mechanical ligations of living tissues using surgical sutures require a combination of a thread and needle. In most cases, the needle diameter far exceeds that of the suture and the needle-to-suture diameter can be as high as 2:1 or 3:1. This can result in leakage of bodily fluids, including blood, through needle-created holes about implanted suture thread. Depending on the surgical site, this can lead to bleeding and infection. A few attempts have been made in earlier decades to minimize needle hole leakage without achieving a clinically optimum solution.
In a study by C. M. Miller and coworkers [Surgery, 10(2), 156 (1987)] on reduced anastomotic bleeding and reduction of blood loss from a vascular anastomosis when one is using an expanded polytetrafluoroethylene (ePTFE) graft, two sutures were used, one made of ePTFE and the other of polypropylene, which were designed to have a needle-to-suture diameter ratio of about 1:1. Theoretically, this allows the suture to completely fill the graft needle hole and control bleeding. These sutures were evaluated in a heparin-treated, canine in vivo model to measure graft needle-hole bleeding. Results of the study, along with subjective evaluations of the sutures' handling qualities led to the conclusion that sutures produced with needle-to-suture ratios of 1:1 greatly reduce graft needle-hole bleeding and will be a useful addition to the vascular surgeon's armamentarium.
In an approach to prevent needle-hole bleeding during vascular anastomosis using expanded polytetrafluoroethylene (ePTFE) grafts treated with sealants, investigators of the prior art noted that Fibrin Glue (FG) is more effective than a thrombin-soaked gelatin sponge for achieving hemostasis of needle- or suture-hole bleeding. However, the risk of infection associated with these naturally derived sealants was not ruled out.
Fibrin glue is frequently used to seal and cover the anastomoses in many operations. However, in the case of gastrointestinal surgeries, the anastomoses are potentially contaminated and FG may promote bacterial growth, thus increasing the risk of leakage
The above-noted accounts of the prior art dealing with different approaches to minimize suture- or needle-hole bleeding or leakage and associated undesirable outcomes illustrate the limited success of the prior art investigators in providing a clinically optimum solution to this problem. This prompted the pursuit of the present invention which deals with the development of a broad range of novel, bioswellable, absorbable and non-absorbable sutures, which can be used more effectively in minimizing or eliminating suture- or needle-hole leakage under the prevailing conditions of several surgical procedures.